Cakbuketor



May 31 1927.

G. M. BICKNELJ.

CARBURETOR Filed March A31. 1921 Y 2 Sheets-Sheet 2 Patented May 3l, 1927.

raras vGEORGE M. IBICKNELL, OF ST. LOUIS, MISSOURI.

CARBURETOR.

Application ledll/Iareh 31, 1921. Serial No. 457,247.

My invention relates to improvements in carburetors and has for its primary object the construction of a carburetor with few moving parts and capable of supplying a large volume of fuel when required without materially enlarging the same.`

A further object is to 'construct a carburetor that will maintain a uniform quality of mixture throughout its throttling range l and make due provision for a proper supply of fuel for pickup or acceleration under any condition of throttle opening either rapid or gradual.

A further object is to construct a carburetory having an adjustable idling tube that will properlyA idle an engine with the throttle set for a certain speed and continue to ldeliver a uniform mixture therefrom throughout the initial stages j of throttle opening until sufficient suction has been applied to the main fuel nozzle to insure a proper flow of fuel therefrom.

The tendency at the present time in the construction of internal combustion engines Aincrease their power through greater engine speed which makes it necessary to use larger carburetors in proportion to the size ofthe engine and consequently, a larger choke or venturi. This choke must .be of a suficient size" to supply the necessary volume of mixture for the greatest motor speed and to successfully use a carburetor of this construction, it has been found advantageous to increase the range of the lowV speed or idling device as much as possible, so that a relatively large volume'of air is passing through the choke at the time the main fuel nozzle takes up the load and supplies the fuel for the mixture..

ln the drawings,

Fig. 1 is a side elcnat carburetor. l

Fig. 2 an enlarged vertical longitudinal sectional view of the same.

Fig. 3 a fragmental vertical section of a portion of the carburetor and the adjustable idling device. j

Fig. 4 an enlarged section taken on the line 4-4 of Fig. 2 and viewed inthe direcf tion of the arrow. y i

Fig. 5 an enlarged elevation of the fuel tubes in the mainfuel nozzle.

s 1n the construction of my device l 'provide a carburetor comprising a housing 6 which ion of my improved has integrally therewith a float chamber il.

r is to reduce the-piston displacement and to in this chamber is contained the float 8 which operatesthe needle valve 9. This is for the purpose of maintaining apre-detervmined l vel of fuel within the chamber 7.

,housing is also provided with the air inlet 13 and the mixing chamber 14.

In the lower portion of the mixing chamber 14 is located a choke or venturi 15. Located in the upper portion of chamber 14 is a sleeve 16. In' this sleeve 'is a butterliy valve 17 having. its stem 18 extending through one side of the carburetor housing and to this extending portion is attached an arm 19 which is connected to the throttle lever. Near the upper portion of the mixing chamber 14 is a recess or auxiliary chamber20 in which the upper end of a tube .21 is located. This tube is ywhat is termed the idler tube and is for the purpose of supplying fuel to the engine while the same is being run idly or at low speed. Formed in sleeve 16 is an'opening 22.y This opening is preferably oval in form and is so arranged as to open into the recess 20. The tube 21 is located in the bore 23 which is formed in the carburetor casing. lThe lower end of this bore is screw threaded as at 24 and in this screw threaded portion is located the adjusting screw 25, the purpose of which is to adjust the tube 21 upwardly or downwardly as required. The purpose of this adjustment will be explained in detail later. Near the upper end of the tube 21 are lformed grooves 26, 27 and 28 and lin these `grooves are formed openings 29, 30 and 31. These openings communicate with the interior of the tube 21. Secured to the lower end. of the adjusting screw 25 and communieating with the tube 21 is a tube 32 which extends into vthe opening formed in the carburetor casing. This opening communicates with the passage 11 and to limit the rapidity of fuel flow in opening 33 the calibrated plug 34 is employed. Secured in the well 12 is a vertical projecting casting or lll() stand pipe 35 and in the upper end of this is seated al nut 36. This nut is preferably a y spider., so as to leave passage way 37 for the admission of*V air into the chamber 38. Projecting upwardly from nut 36 is the main fuel nozzleBQ. This nozzle projects up into the venturi 15. to the underside of si?! i nut 36 lea* bridge T40 and projecting through this bridgthre the'rfuel tubes 41,` 42 and `43.` Their upper ends extending into the nozzle 39. -It will also be noted-that-the upper'ends of the tubes all terminate in the same plane,

While their lower ends project to vaiousffwitl'out loa distances below the bridge 40. `Secured to the nozzle 39 is a cap 44`fwliich-is pi'o'videidJ on one lside witha rack 45 which meshes.

withl the pinion 46; This pinion has its shaft 4T projctingthrough the sideof the carbu'- ,retor casing' and to this project-ing `shaft is` secui'ed"a.lever'flf` Thislever has its free end attached to a suitable lcontrolling .means forswinging the lever which operates the cap44iup and down, so astoincrease or reduce the `amount air fiowing through .the choke. This is 'for tliepurposeof pruning the engine when the saine is started or when it is desired 'to increase the flow of fuel thiough theimain nozzle.v The lower )o1-tion of the'cap'44 is provirjled with'opeiungs 49' which admit air to the interior 'of the cap.`

This air passing downward through the openingv 37 and then into the tubes 41, 42

and 43i and is for the purpose of eompen` Satine` 'for increased suction due toincreased engine speedl Thewell and stand pipe'aresofarrangedthat the gasoline level lwill be a proximately even with the `undersidebf operated; *Theoperation of my :device is as Afollows :A v

Thie .pi 'e 21 is firsbpositioned by means of the: a justing screw so that the groove' 26`iind opening 29 will be slightly above the' valve'l'? when the same lis partially opened. This will alldwvthe openings 29 to communicate'with the suction portion of thernixing` clia'mber 14 above the valve 17. After the carburetorlias beenassembled und attached to the engine, the' pipe 21 is first positioned" byineansof theadjusting screw so that' thelgroove .26 and iopenings 29 will 'be slightly above the valve 17 when the same is'partially `open.` VVhe-n in `this position valve 17 into' the engine' andthe suction created thereby moving past the opening QQ'inthe sleeve 16 Awill draw air out' ofv thfupper'portion 'of the auxiliary chai-n4 bei* Q0. f Any air which `enters thecarburetor below "tli'e 'valvef will inot 'only pass laround fthevalve but a portion thereof will also be drawn thr'ough lthe opening intoth'e vauxil-` iai' i chamber 20,a`n'd will also enter through i the openings BOfiand 31 and. pass `out through thebpenigSO. 'and 311 'and' passingout through theopenings 29will causeii partial vacuuiito be formed in the "idler tube the opening 30 above the throttle "valve and raise` fuel tlieieini'iwliich filial *will be dischai'gedthrough the openingsQQ and into the mining chamber above the Valve 17. The .amountof fuel thus `delivered is Isufficient to keep the enfrine turning over or running At. this point the throttle valve is almost entirely closed and the suction-@createdin'theauixiliai'y chamber 20 is supplied thi'oughtlie opening 2?.` which is adjacent the 1edge 'of the throttle valve when in itsidl'ing position.

The needlevalve 10 is then afdjustedso asl tol permit .sufficient -fuel to `flow froiirthe/1 floatrhambei'i Vinto Ythe passage 11 `and well l2, the flow offfuel beinggreatei than' that demanded by the idler tube so that the fuel wil'lraisein the" well to a suflici'entflheight to submergethe lend of-the tube 41.l This fuel levelhoweverris controlled by thefiioat 8, in other words, when the fuel in the well 12 reaches this llevel the floatautomatically closes oil' the supply line so'that the eari buietor will'notv become` flooded: As the throttle valve is opened 'its edge vadjacent the` passage' or opening 22 inovesdownward, this decreases 'the `space in "which the' air can How into'the'auxiliary .chamber Q0 and en# larges its outletl and atthe same' time Vbrings All of lthe ilowbf air into'the' idling jet is :now through the openings V31, whilefiil'is delivered through the openings 29211111.30.

A still ifarther opel'iii'ig'jolf the throttle" valve permitsy they openings 31 5to; 'also ydelive'r' `fuel. When thisrtakes place the throttle `v'alve'is sufficiently opened to permit air to straight upward past the oassag;e"22.V

passage'of airV has avsiphoning'action and di'awstlie air from the auxiliary chamber20 which is replacedbyfuel throughthe openings 29, BOand 31." While this siphoning action "iii the auxiliary chamber" 20`is taking `place; siphoning action"also `commences on tlie'main jet 39,'by`reasoii of thepassage of air throughthe venturi or choke" 15 andas airis withdrawn rom the mainv ]et 39 a 49 wliicliis permitted by means oftliespider 36.A The "aii"l rushingv` through the nozzle 39 creates a suction in the tubes 41, 42`iind'43. i'

l I i .i n i These tubes as soon as suction is crea-ted tliei'ein,` commence'to deliver fuellv' Atthis' period theeu-gie 'is ruiming at 'a higher `speed and' consuming more 'fuel th'aii'thef needle valve 10 allows to pass. In other words, a mixture 'rich iny 'fuel is benigno livered tothe engine. As soon as the wer portion of. the pipe 41 is uncovered; any y y suction created therein delivers only` air and theopenings529. This air entering through p fuel. This delivery of fuel by both of these permits only the pipes 42 and 43 to deliver pipes continues untiltheopening `s iin- 1100 ,pes Y his lilo of air and fuel is delivered by the pipe 42, While the pipe 43 still continues to deliver its full fuel only and an increase in speed further lowers the fuel level until the lower end of the pipe 42 is uncovered. At this period both pipes 41 and 42 deliver only air, or rather a small quantity, which is drawn therethrough by means of the suction created in the main nozzle 89. The pipe 43 is new the sole source of supply and continues lowering the fuel level until the opening 51 therein is uncovered, after Which it also delivers a mixture of air and fuel. rlhis delivery of fuel is sufficient to keep the engine ruiming at high speed and in furnishing the proper mixture, in other Words, the construction of the tubes and regulation of the valve l() is such that a properly proportioned mixture for running the engine at high speed will be maintained. As soon as the engine is throttled down so that the quantity of fuel necessary to maintain the speed of the engine is reduced the fuel level will rise in the Well and the delivery of fuel to maintain this reduced speed be divided between two pipes. A further sloWin g down of the engine will bring into action all three pipes, but the suction being decreased by the slowing down of the engine a proper amount of mixture Will still be delivered, so that an increased amount of fuel is available for acceleration and upon the entire throttling down of the engine to its lowest or idling speed the fuel level in the Well and float chamber will be restored so that the engine can be readily accelerated. ln this Way my carburetor supplies an extremely rich mixture, for sudden acceleration, which gradually leans down automatically as the engine speed increases. The richest mixture being delivered only temporarily and not for a suiiiciently long enough time to choke the engine with an over rich mixture. ln other Words with my carburetor, it is practically impossible. to stall the engine due to sudden acceleration flooding the cylinders which nia-kes it extremely useful when an automobile driver is caught traveling slowly in a dangerous position, such as on railroad crossings, ete., and must depend upon sudden acceleration lo get out of dangm' as there is very little possibility of killing the engine due to sudden acceleration when my device is employed. Furthermore with the construction of my device` the leaving off ofl the idler jet action and the bringing into action of t-hc'maln nozzle overlap each other either on speeding up or slowing downso that there is no sudden leavingr off of one. and bringing` on action of the other, With the consequent possibility of a dead spot in between, which might kill the engine and cause a serious accident. Heretofore it has necessitated extremely delicate adjustment and relatively large carburetor to permit a sudden increase in speed Without choking lthe engine, for the reason that a small carburetor has a relatively small Well and upon sudden acceleration a rich mixture was fed to the engine which continued until practically all of the fuel in the Well was cxhausted. lt was therefore necessary to malte use of a large carburetor and one which Was apable of supplying more fuel at all times than Was really needed by the engine. A carburetor of this kind necessitated Lthe use of many adjusting screws which when handled by inexperienced persons led to constant trouble and complaints.

l't is to be understood of course that in the slowing down of the engine which brings into action all three pipes, that the suction created by the engine reduces the speed at which the air travels through the main nozzle and consequently although all three pipes may be delivering fuel the amount of fuel drawn from the pipes will be just suiiicient to furnish a lean mixture for that particular speed of engine.

ltis furthermore to be noted that upon sudden acceleration the mixture is leaned out automatically, thelirst suction or two tending the uncover the lower end of the pipe 41, so in other Words, the engine is only supplied momentarily With an extremely rich mixture. This mixture being approximately sutiicient to charge each cylinder once, after which the mixture is partially leaned out, which leaning out process continues until only the pipe 43 is in action.

Having fully described my invention, what l claim, is: K

ln a carburetor comprising a lusing v.having a `float chamber, a mixing chamber,

GEORGE M. BICKNELL.

lHU 

